US 12,305,989 B2
Resonator optical gyroscope with diminished bias error
Jianfeng Wu, Tucson, AZ (US); Tiequn Qiu, Glendale, AZ (US); and Matthew Wade Puckett, Phoenix, AZ (US)
Assigned to Honeywell International Inc., Charlotte, NC (US)
Filed by Honeywell International Inc., Charlotte, NC (US)
Filed on Feb. 9, 2023, as Appl. No. 18/166,792.
Prior Publication US 2024/0271937 A1, Aug. 15, 2024
Int. Cl. G01C 19/72 (2006.01)
CPC G01C 19/727 (2013.01) [G01C 19/721 (2013.01); G01C 19/722 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A method for reducing bias error in a resonator optical gyroscope, the method comprising:
receiving, at a first polarizing beam splitter (PBS) from an optical source, a clockwise (CW) optical signal comprising a first mode and a second mode, wherein the first mode is a transverse electric (TE) mode or a transverse magnetic (TM) mode and the second mode is respectively the TM mode or the TE mode;
receiving, at a second PBS from the optical source, a counterclockwise (CCW) optical signal comprising the first mode and the second mode;
suppressing, with the first PBS, energy of the second mode of the CW optical signal more than energy of the first mode of the CW optical signal is suppressed by the first PBS;
suppressing, with the second PBS, energy of the second mode of the CCW optical signal more than energy of the first mode of the CCW optical signal is suppressed by the second PBS;
receiving, at a travelling wave resonator system from the first PBS, at least a portion of the CW optical signal with the second mode whose energy has been suppressed more than the energy of the first mode of the CW optical signal, wherein the travelling wave resonator system comprises a travelling wave resonator configured to propagate an optical signal in only one direction;
receiving, at the travelling wave resonator system from the second PBS, at least a portion of the CCW optical signal with the second mode whose energy has been suppressed more than the energy of the first mode of the CCW optical signal;
in response to at least a portion of the CW optical signal, with the second mode whose energy has been suppressed more than the energy of the first mode of the CW optical signal, provided by the travelling wave resonator system, adjusting a carrier frequency of the CW optical signal emitted from the optical source to equal a resonant frequency of the travelling wave resonator in a CW direction;
in response to at least a portion of the CCW optical signal, with the second mode whose energy has been suppressed more than the energy of the first mode of the CCW optical signal, provided by the travelling wave resonator system, adjusting a carrier frequency of the CCW optical signal emitted from the optical source to equal a resonant frequency of the travelling wave resonator in a CCW direction; and
in response to either (a) a portion of the CW optical signal, with the second mode whose energy has been suppressed more than the energy of the first mode of the CW optical signal received from the first PBS, and a portion of the CCW optical signal, with the second mode whose energy has been suppressed more than the energy of the first mode of the CCW optical signal received from the second PBS, or (b) a portion of the CW optical signal, with the second mode whose energy has been suppressed more than the energy of the first mode of the CW optical signal, received from the travelling wave resonator system, and a portion of the CCW optical signal, with the second mode whose energy has been suppressed more than the energy of the first mode of the CCW optical signal, received from the travelling wave resonator system, determining a rate of rotation of the resonator optical gyroscope around a center axis of the travelling wave resonator.